Why We Are Secretly Attracted To People Who Look Like Our Parents

Just heard the news? Relax, it doesn’t mean you fancy your mum. Monkey Business Images

Have you ever thought there was an uncanny family resemblance between your friend and her partner? Or wondered for a fleeting moment whether the pair walking down the road were husband and wife, or brother and sister? You might not be imagining things. Animals of many species “learn” what a suitable mate looks like based on the appearance of their parents, and so, it seems, do humans.

This isn’t Freud’s Oedipus complex revisited. Freud believed that children have a suppressed desire for their parents. But this branch of research doesn’t in any way show that we secretly desire our parents, just that we simply tend to be attracted to people who resemble them to some extent.

If anything, we seem to find our immediate family members unattractive. For instance, people find the very idea of sexual relationships with their siblings deeply unappealing. This aversion seems to develop automatically through two distinct processes. One process turns off attraction to those that we spend a lot of time with during childhood. The other turns off attraction to any infants that our mother looks after a lot. Sexual aversion to siblings might be nature’s way of ensuring we don’t try to reproduce with someone who is too closely related to us and reproduction with close relatives is linked to an increased likelihood of genetic disorders in any resulting offspring. This aversion to close relatives is known as negative sexual imprinting. However, genetic sexual attraction can occur between siblings that have been separated and meet first as adults.

How close we are to our parents at different ages seem to influence our choices of partner. Tom Wang

But when do we develop these preferences? Perhaps we learn that our parents looks are attractive early in life, and then tuck that learning away – only to let it reemerge when we’re ready for adult relationships. Or perhaps more recent experiences override earlier learning? To test this, I asked heterosexual adult women about their relationships with their parents at different ages during their development, and I assessed how much their current preferences matched up with the appearance of their parents.

I found that the women who reported a better relationship with their parents after puberty were more likely to be attracted to partners with similar eye colour to them. In contrast, if a woman was close to her parents earlier in life, she was actually less likely to prefer the eye colour of her parents in a partner. In science, we always like to see replications with different samples, methodologies and research groups before we generalise findings too much. So far though, the intriguing pattern of this early study suggests that there may be complex developmental patterns underlying how we construct our idea of an ideal partner. Perhaps we are seeing the actions of both positive and negative sexual imprinting at work.

But one question remains. If we’re finding preferences for parental resemblance across different populations, then what is the biological explanation for this behaviour? It turns out that coupling up with a distant family member seems to be the best bet, biologically, to produce a large number of healthy children. One possibility is that if you are attracted to people who look like your parents, then chances are you may get a crush on distant relatives. This might give you better chances of more healthy children, and so this behaviour persists.